Compositions and methods employing Wolbachia FtsZ as a target for Albendazole sulfone

ABSTRACT

Compositions and Methods are described in which Albendazole sulfone binds to Wolbachia FtsZ providing anti filarial activity.

RELATION TO OTHER APPLICATIONS

This application claims priority to and the benefit of U.S. provisionalapplication No. 61/553,214 filed 30 Oct. 2011 which is herebyincorporated by reference for all purposes.

FIELD OF THE INVENTION

The invention relates novel uses of drugs for treating filarial disease.

BACKGROUND

Wolbachia are obligate-intracellular, maternally transmitted bacteria.Antihelminthic drugs have been widely used to combat LymphaticFilariasis and African River Blindness. A significant drawback ofantihelminthic therapies currently used to treat River Blindness andLymphatic filariasis is that they simultaneously target other nematodeinfections as well. This is a particular problem in areas where peopleare co-infected with Loa loa and either O. volvulus or B. malayi. Ineffort to identify new anti-Wolbachia therapeutics, we developed aWolbachia-infected Drosophila cell line and conducted a high-throughputscreen to identify compounds that reduced intracellular Wolbachiainfection.

BRIEF DESCRIPTION OF THE INVENTION

Albendazole sulfone, a metabolite previously thought to be inactive,disrupts Wolbachia FtsZ, a key binary fission protein, in Brugia malayinematodes associated with Lymphatic Filariasis.

SHORT DESCRIPTION OF THE FIGURES

The figures are shown and described as attached. The figures prove thatAlbendazole sulfone disrupts Wolbachia Fts Zin Brugia malayi.

FIG. 1A shows Wolbachia disruption in interphase of JE18 cells. FIG. 1Bshows Wolbachia disruption in interphase of JW18TET cells. FIG. 1C showsWolbachia disruption in prophase. FIG. 1D shows Wolbachia disruption inprophase. FIG. 1E shows Wolbachia disruption in metaphase. FIG. 1F showsWolbachia disruption in late anaphase.

FIG. 2 Chemical screen method

FIG. 3A is Albendazole. FIG. 3B is Albendazole sulfoxide. FIG. 3C isAlbendazole sulphone. FIG. 3D is NSC96932. FIG. 3E is NSC339601. FIG. 3Fis NSC120982.

FIG. 4 Effect of Albendazole on Wolbachia

FIG. 5A shows stage 10A oocytes stained with Propidium iodide, treatedwith DMSO. FIG. 5B shows stage 10A oocytes stained with Propidiumiodide, treated with Albendazole sulphone. FIG. 5C shows stage 10Aoocytes stained with Propidium iodide, treated with colchicine. FIG. 5Dshows stage 10A oocytes treated with anti-alpha tubulin and withcolchicine. FIG. 5E shows stage 10A oocytes treated with anti-alphatubulin and with Albendazole sulphone. FIG. 5F shows stage 10A oocytestreated with anti-alpha tubulin and with colchicine.

FIG. 6 Wolbachia disruption by Albendazole.

FIG. 7 Table showing asymmetric distribution of Wolbachia in mitoticcells

GENERAL REPRESENTATIONS CONCERNING THE DISCLOSURE

The embodiments disclosed in this specification are exemplary and do notlimit the invention. Other embodiments can be utilized and changes canbe made. As used in this specification, the singular forms “a”, “an”,and “the” include plural reference unless the context clearly dictatesotherwise. Thus, for example, a reference to “a part” includes aplurality of such parts, and so forth. The term “comprises” andgrammatical equivalents thereof are used in this specification to meanthat, in addition to the features specifically identified, otherfeatures are optionally present. Where reference is made in thisspecification to a method comprising two or more defined steps, thedefined steps can be carried out in any order or simultaneously (exceptwhere the context excludes that possibility), and the method canoptionally include one or more other steps which are carried out beforeany of the defined steps, between two of the defined steps, or after allthe defined steps (except where the context excludes that possibility).Where reference is made herein to “first” and “second” features, this isgenerally done for identification purposes; unless the context requiresotherwise, the first and second features can be the same or different,and reference to a first feature does not mean that a second feature isnecessarily present (though it may be present). Where reference is madeherein to “a” or “an” feature, this includes the possibility that thereare two or more such features.

This specification incorporates by reference U.S. provisionalapplication No. 61/553,214 and all documents referred to herein and alldocuments filed concurrently with this specification or filed previouslyin connection with this application, including but not limited to suchdocuments which are open to public inspection with this specification.

Where KCl is mentioned, this salt is used as an example only, and KClmay be substituted in all instances for any other monovalent salt.

DEFINITIONS

The following words and phrases are used herein as follows:

The terms “pharmaceutical formulation” and “pharmaceutical composition”mean any composition intended for administration to a human being orother mammal and comprises at least one drug; it may also include one ormore other additives, for example pharmaceutically acceptableexcipients, carriers, penetration enhancers, stabilizers, buffers orother materials.

The term “drug” means any substance that alters the physiology of anorganism. Multiple drugs may be included in a single formulation.

The term “therapeutically effective amount” means an amount of atherapeutic agent, or a rate of delivery of a therapeutic agent,effective to facilitate a desired therapeutic effect.

The term “treatment” means the application of a process to an individualin order to alter a physiological state, whether or not the processincludes a curative element.

“Controlled” release of a drug means release of the drug in apre-determined or adjustable way such that the amount or rate or timingof release is pre-set or is altered in a desired way.

“Sustained” release of a drug means release over an extended period oftime, for example minutes, hours or days. such that less than all thedrug is released initially.

The term “subject” means any subject, generally a mammal (e.g., human,primate, canine, feline, equine, bovine, fish, birds etc in whichmanagement of a disease is desired.

DETAILED DESCRIPTION OF THE INVENTION

Wolbachia bacteria carried by filarial nematodes give rise to theneglected diseases African River Blindness and Lymphatic Filariasis inmillions of people worldwide. In effort to identify new anti-Wolbachiatherapies, we conducted a high-throughput chemical screen usingWolbachia-infected tissue culture cells. This screen yielded severalcompounds that resembled Albendazole, an antihelminthic drug used totreat millions of people with neglecte disease. Follow-up testing ofAlbendazole and its metabolites in Drosophila oogenesis showed that themetabolite Albendazole sulfone exerted anti-Wolbachia activityequivalent to Doxycycline. Immunostaining indicated that Albendazolesulfone treatment disrupts Wolbachia FtsZ, a key binary fission protein,in Brugia malayi nematodes associated with Lymphatic Filariasis. Thishighlights Albendazole sulfone as a potential new treatment forneglected disease as well as a starting point for developing a new classof anti-Wolbachia compounds

Wolbachia are obligate-intracellular, maternally transmitted bacteria.They were initially studied because of the unconventional reproductivephenotypes they induce, namely sperm-egg cytoplasmic incompatibility,feminization of males, male-killing, and parthenogenesis. More recently,Wolbachia have become recognized as a major global health concern.Wolbachia are essential endosymbionts of filarial nematodes associatedwith the diseases Lymphatic Filariasis and African River Blindness thatcurrently afflict 30 million people, with upwards of 400 million more atrisk. Recent work indicated that the Wolbachia carried by thesenematodes act as the causative agent of River Blindness and likelyunderlie much of the inflammatory reaction in Lymphatic Filariasis. Thiscreates a need for effective anti-Wolbachia therapies to better addressthis major global health issue.

Antihelminthic drugs have been widely used to combat LymphaticFilariasis and African River Blindness to date. These drugs directlytarget essential processes in the nematodes associated with thesediseases, namely Onchocerca volvulus, Brugia malayi, and Wuchereriabancrofti. Ivermectin disrupts glutamate-gated chloride channels thatcontrol release of excretory/secretory vesicles that would normallysuppress the immune response. Diethylcarbamazine is used to target thearachidonic acid pathway, shutting down a major metabolic pathway of thenematode. Albendazole is used to disrupt the nematode microtubulecytoskeleton. Orally administered Albendazole is rapidly metabolized bythe liver into Albendazole sulfoxide and Albendazole sulfone.Albendazole sulfoxide is commonly referred to as the “active,”antiparasitic form of Albendazole, while Albendazole sulfone isconsidered to be an inactivated form of the drug.

A significant drawback of antihelminthic therapies currently used totreat River Blindness and Lymphatic filariasis is that theysimultaneously target other nematode infections as well. This is aparticular problem in areas where people are co-infected with Loa loaand either O. volvulus or B. malayi. Loa loa migrates into the brain,and as such, general antihelminthic treatments cidal to Loa loa triggera potentially lethal inflammatory cascade in the brain. The limitationon usage of antihelminthic treatments in these areas of co-infectioncreates a reservoir where filarial parasites can persist indefinitely.Targeting Wolbachia offers a means of distinguishing between theseparasitic infections, as the nematodes that cause River Blindness andLymphatic filariasis are reliant upon Wolbachia endosymbionts and Loaloa is not. Antibiotics such as Doxycycline are being used to addressthis treatment gap, though extended treatments are required forefficacy.

In effort to identify new anti-Wolbachia therapeutics, we developed aWolbachia-infected Drosophila cell line and conducted a high-throughputscreen to identify compounds that reduced intracellular Wolbachiainfection. This screen yielded several Albendazole-like compounds.Follow-up testing of Albendazole and its metabolites in Drosophilaoogenesis showed that the metabolite Albendazole sulfone exertedanti-Wolbachia activity equivalent to Doxycycline. Immunostainingindicated that Albendazole sulfone treatment disrupts Wolbachia FtsZ, akey binary fission protein, in the disease model B. malayi. Thishighlights Albendazole sulfone as a potential new treatment forneglected disease as well as a possible starting point for generating ofa new class of specific anti-Wolbachia compounds.

Methods

Generation Cultured Cells

The JW18 cell line was generated as previously. Embryos were collectedfrom Wolbachia-infected flies carrying a Jupiter-GFP transgene {Karpova,2006 #129}, then homogenized and plated in flasks. During the next sixmonths of maintenance, a subset of flasks converted into immortal tissueculture lines, including the JW18 cell line. A cured version of the JW18line was made by treating the cells with Tetracycline at 100 ug/mL forone month.

Screening Approach

Cells were plated in 384-well, clear bottom plates (Griener Bio-one)pre-coated with 0.5 mg/mL Concanavalin A. JW18 cells were added to 22columns, and JW18TET cells were added to the remaining 2 columns at adilution of 6500 cells per well. After the cells adhered to the plates,compounds were transferred into 20 columns of JW18 cells in the centerof the plate using a Janus MDT pin tool. The final concentration ofcompound was 100 uM per well. All treatments were distributed into 3plate replicates.

After a 5-day incubation with the compounds at 25 C, the cells wereprepared for imaging. Cells were fixed for 20 minutes in 4% formaldehydeand rinsed with PBS using an automated BioTek liquid handler. Allstaining solutions were administered using a Multidrop robot, withextensive rinsing between treatments. The primary antibody, mouse antihistone (MAB052, Millipore), was used at 1:1250 in PBS/0.1% Triton.Secondary antibody goat anti-mouse Alexa 594 (Invitrogen) was used at1:1250. DAPI was used as a saturated solution, diluted to a finalconcentration of 1:40. After staining, PBS+Azide was added to all wellsof the plates.

Screen Data Analysis

Stained treatment plates were imaged using the MetaExpress Micro system(Molecular Devices, Sunnyvale Calif.). 10 images were acquired per wellat 40× magnification. These images were next analyzed using customizedjournaling software provided by Molecular Devices. The journal firstmasks any areas where clumps of cells are detected, based upon intensityof the Jupiter-GFP. The boundaries of the remaining cells and theirnuclei are recognized based upon the Jupiter-GFP and anti-histonestains. A mask is applied to the nuclei, to obscure the hi stone andDAPI signal from those areas. A threshold for DAPI fluorescencedetection is set to detect as much Wolbachia as possible in JW18 controlcells while minimizing detection of background DAPI signal in JW18TETcontrol cells. Then this cytoplasmic DAPI level, read to indicateWolbachia, is scored in the cytoplasm of individual cells to determinewhether each cell is infected with Wolbachia. The cutoff valuedistinguishing “infected” from “uninfected” cells is 4000-5000fluorescence units per cell. This is considered to be a low cutofflimit, as some infected cells exhibit over 100,000 cytoplasmic DAPIfluorescence units.

A spreadsheet from the journal indicates the quantity ofWolbachia-infected cells versus total cells measured in each well. A Z′factor is calculated for each plate based upon the average frequency ofcell infection for JW18 and JW18TET control cells. Our Z′ factors perplate range from 0.2 to 0.65. An initial hit range is calculated to liebetween the JW18 average infection frequency−3 standard deviations, andthe average JW18TET infection frequency+3 standard deviations. Tofurther refine identification of hits, we also calculated an averageinfection frequency for all JW18 cells on the plate (treated or not), asmost treatment wells are expected to be indistinguishable from untreatedcontrols. Wells are that lie within 3 standard deviations of the meanare exluded, and remaining wells are classified as hits within thatreplicate. Hit wells that are identified in at least 2 out of 3replicates are considered to be finalized hits.

Drug feeding conditions: Fly feeding we done as previously described.

Staining: Drosophila Ovary staining was done with with PI, anti-tubuli.Drosophila Embryo staining was done with with anti-FtsZ. Brugiamicrofilarial staining was done with with PI, anti-tubulin, andanti-FtsZ.

Results

Development of a Drosophila Cell Line Constitutively Infected WithWolbachia

To identify compounds that affect intracellular Wolbachia titer, wefirst generated Drosophila tissue culture cells that arc constitutivelyinfected with Wolbachia. The cell line used for this study, JW18, isamenable to high throughput screening in that it expresses a Jupiter-GFPfusion protein that binds host microtubules {Karpova, 2006 #129}.Wolbachia are carried within 88% or more of the host cell population(n=1053 cells scored). Comparing JW18 to Tetracycline-cured JW18 cellsshowed no significant difference in mitotic index, with a frequency of0.27% observed for JW18 and 0.68% for JW18+Tet (n=1867 and 2339,respectively). Additionally, no significant difference was observed inthe frequency of binucleate cells between JW18 (9.1%, n=873) andTetracycline-cured JW18 cells (10.5%, n=1081). Thus, Wolbachia do notexert an obvious influence on progression of the host cell cycle in theJW18 cells.

To test whether Wolbachia exhibit normal interactions with the hostcell, bacterial localization patterns were examined in the JW18 cellline. In interphase cells, many Wolbachia were closely juxtaposed withJupiter-GFP-labeled microtubules (FIG. 1A-B). Live imaging indicatedthat Wolbachia can move processively along those interphase microtubules(Supplementary Movie 1), consistent with earlier reports ofWolbachia-microtubule interactions. In mitotic cells, Wolbachia wereasymmetrically distributed throughout the cytoplasm 82% of the time(n=56, FIG. 1C-F, Suppl Table 1), reminiscent of Wolbachia localizationpatterns observed in embryonic and larval neuroblasts {Albertson, 2009#127}. These data indicate that Wolbachia distribution in the JW18 cellline is consistent with that of intact Drosophila tissues.

Identification of Wolbachia-reducing compounds by high-throughputscreening. The JW18 cells were implemented in a high-throughput screento identify anti-Wolbachia compounds. High-throughput screening is awell-established approach for testing chemicals and RNAi moleculesagainst a variety of cell types. In this screen, 3081 compounds froththe National Cancer Institute were used. The collection includedstructurally and functionally diverse synthetic compounds as well as aset of natural products. Cells were incubated for 5 days with eachcompound, then fixed, stained, and imaged using automated robotics (FIG.2). Customized analysis software was used to compare the images fromcompound-treated wells to the control cells to assay for significantchanges in the quantity of Wolbachia-infected cells. All treatmentplates were run in triplicate.

From this screen, 23 preliminary candidate anti-Wolbachia compounds wereidentified. These compounds reduced the Wolbachia-infection frequencyinto the hit range in at least 2 out of 3 replicates tested, and alsofell outside the range of 98.5% of the data (Suppl Table 2). A number ofthese hits have previously been implicated as having antimicrobialactivity, consistent with what would be expected from the screen. Twocompounds, Cinerubin B and Mitomycin B are structural derivatives of theanticancer antibiotics Daunorubicin and Mitomycin, which are approved bythe FDA for use as chemotherapy agents. NSC207895 is a DNA damagingagent. Pyronin B is a quaternary ammonium compound, many of which serveas the antimicrobial agents in commercial disinfectants. One othercompound, NSC96932 has also been shown in a prior screen to exertantibacterial activity against Streptococcus pyrogenes.

To investigate the basis for the anti-Wolbachia activity of theantibacterial NSC96932 compound, we examined its chemical structure.This revealed that NSC96932 is a benzthiazole sharing some structuralsimilarity with Albendazole, the widely used antihelminthic drug knownfor disrupting microtubules (FIG. 3). Examining the structural featuresof all other hits in our screen indicated that two additionalanti-Wolbachia compounds that share structural similarity toAlbendazole, the benzthiazole NSC150982 and the benzimidazole NSC339601.This implies that Albendazole-like compounds share a commonanti-Wolbachia activity.

Wolbachia Titer in Drosophila is Reduced by Albendazole Sulfone

As Albendazole is already a widely used, FDA-approved drug, we proceededto test it and the primary metabolites Albendazole sulfoxide andAlbendazole sulfone for anti-Wolbachia effects in Drosophila oogenesis.This system provides a high-precision method for assessing Wolbachiatiter in a well-characterized developmental context. After a 24-hourtreatment period, Wolbachia counts from single oocyte focal planesindicated that Albendazole-treated flies had 194+/−20 Wolbachia peroocyte, and Albendazole sulfoxide exhibited 255+/−27 Wolbachia peroocyte, which was not significantly different from the DMSO treatedcontrol (225+/−18 Wolbachia per oocyte, FIG. 4A). However, Albendazolesulfone-treated oocytes had significantly less Wolbachia than thecontrol, with 150+/−13 Wolbachia evident per oocyte. This matched theWolbachia depletion seen in Doxycycline-treated oocytes, which exhibited126+/−11 Wolbachia (FIG. 4A). Thus, Albendazole sulfone exhibits asignificant anti-Wolbachia effect in Drosophila.

Albendazole sulfone affects Wolbachia titer in a microtubule-independentmanner. Albendazole and structurally similar benzimidizoles likeNocodazole are thought to disrupt microtubule polymerization by bindingto beta-tubulin. As prior work in Drosophila indicates that Wolbachiatiter is at least partially dependent upon host microtubules, a role forAlbendazole sulfone in reducing Wolbachia titer initially appearssensible. However, prior mutant studies have identified key amino acidswithin beta tubulin that are important for response to benzimidazoles.In particular, N165 and Y200 are thought to form a hydrogen bond,stabilizing the structure of the beta-tubulin, restricting accessibilityto a benzimidazole binding site. Most Drosophila beta tubulins carrythese residues, and thus are not predicted to be susceptible tobenzimidazoles. This presents a puzzle as to the basis for theWolbachia-reduction effect of Albendazole sulfone.

To address whether Albendazole sulfone acts on Wolbachia by disruptingthe oocyte microtubule cytoskeleton, a combination of approaches wasused. It has previously been shown that Wolbachia concentrate at theoocyte posterior cortex in a microtubule-dependent manner. In thisstudy, posterior Wolbachia localization was seen in 95% of DMSO controlsand 93% of Albendazole sulfone-treated oocytes (n=56 and n=46,respectively) (FIG. 6A-B). This differed significantly fromColchicine-treated oocytes, where only 21% exhibited posterior Wolbachialocalization (p<0.001, n=13, FIG. 6C). We also examined the cytoskeletondirectly by immunolabeling the microtubules. DMSO controls andAlbendazole sulfone-treated oocytes exhibited fibrillar microtubulearrays, while the cytoplasm of Colchicine-treated oocytes was devoid offilamentous structure (FIG. 5D-F). This demonstrates that Albendazolesulfone does not affect the overall orientation or structure of theoocyte microtubule cytoskeleton. This suggests that Albendazole sulfoneacts upon Wolbachia in a microtubule-independent manner.

Albendazole Sulfone Acts Against Wolbachia FtsZ

An alternative target for Albendazole sulfone may be FtsZ, a bacterialprotein critical for cell wall assembly during binary fission. FtsZ isthought to be a homolog of eukaryotic tubulin. Alignment of FtsZsequence with tubulin suggests that FtsZ should be susceptible todisruption by benzimidazole treatments (FIG. 5). Prior studies alsoindicate that Albendazole-like compounds can target and disrupt FtsZfunction in Escherichia coli and Mycobacterium tuberculosis.

To investigate whether Albendazole sulfone disrupts Walbachia FtsZ, wefed this compound to Brugia malayi microfilariae, which carry Wolbachiaas an essential endosymbiont. Unlike DMSO controls, the Albendazolesulfone treatment triggered widespread disruption of B. malayimicrotubules. This is consistent with the predicted benzimidazolesusceptibility of B. malayi beta tubulin (FIG. 5). Interestingly, FtsZwas also disrupted in most of the Albendazole sulfone-treatedmicrofilariae, indicating that this compound compromises both Brugiamicrotubules and Wolbachia FtsZ.

In view of the above the inventors posed the questions: By whatmechanism does Albendazole sulfone act against Wolbachia FtsZ? And isFtsZ disruption a consequence of host microtubule disassembly, or due toa separate effect on FtsZ by Albendazole sulfone? Examination ofAlbendazole-sulfone-treated microfilariae revealed instances in whichmicrotubules were disrupted and FtsZ was not (FIG. 6). To further testwhether Wolbachia FtsZ relies on host microtubules, we also treatedBrugia with the microtubule-disrupting drug Colchicine. Though thistreatment severely disrupted host microtubules, FtsZ remainedconcentrated near Wolbachia DNA (FIG. 6). This indicates that hostmicrotubules are not required for FtsZ localization in Wolbachia.Rather, the data suggest that Albendazole sulfone targets Wolbachia FtsZand host microtubules separately in Brugia microfilariae.

Discussion

This study has redefined the mechanism of action used by Albendazole, anantihelmenthic drug that is used to treat millions worldwide withneglected disease. High-throughput screening indicated that severalAlbendazole-like compounds reduce Wolbachia infection in tissue culture.Further tests of Albendazole sulfone, a metabolite previously thought tobe inactive, triggered significant reductions of Wolbachia titer inDrosophila oogenesis. Furthermore, Albendazole sulfone treatment ofBrugia malayi, the filarial nematode associated with LymphaticFilaraisis, yielded disruptive effects against both Brugia microtubulesand Wolbachia FtsZ, an essential binary fission protein. This positionsAlbendazole as a potentially useful tool to use in tandem withDoxycycline for River Blindness and/or Lymphatic Filariasis prevention.

A function for Albendazole sulfone is surprising as this molecule waspreviously described as inactive (Gottschall G W et al 1990). Thisdetermination may have been made in part because the Albendazole sulfonemetabolite is less abundant in human serum and urine than Albendazolesulfoxide. A study testing competitive inhibition of tubulinpolymerization also showed Albendazole sulfone to be a far less potentdisrupter of beta-tubulin than Albendazole sulfoxide. This formerdrawback for Albendazole sulfone may now elevate its usefulness fortreating African River Blindness and Lymphatic filariasis, as a lowerpotency of host microtubule disruption would be expected to reducenon-specific filarial targeting, while ante FtsZ activity wouldsimultaneously provide a more specific anti-Wolbachia effect.

This study suggests that Albendazole sulfone could serve as a startingpoint for generating of a new class of anti-Wolbachia compounds fortreating neglected disease. Other benzimidazoles previously approved bythe FDA have some drawbacks. Thiabendazole was found to be teratogenic,and thus its usage has been discontinued. Mebendazole ismicrofilaricidal, and thus not amenable to areas where patients areco-infected with Loa loa. Flubendazole functions well as amacrofilaricide while leaving microfilariae undisturbed, thuspositioning it well for usage in areas with Loa loa co-infection. Thedrawback of Flubendazole is that it needs to be administered byinjection. in order to function effectively.

The possibility of Albendazole-sulfone-based drug development raises thequestion of how specifically such compounds may target Wolbachia FtsZrather than FtsZ in other bacterial strains. Broad-spectrumantibacterials quickly give rise to resistance genes, and this is aparticular concern for M. tuberculosis, which has become extremely drugresistant in some areas. Comparing FtsZ between bacteria indicatesconsiderable variation in the amino acid sequence, suggesting thatstrain-specific FtsZ targeting may be possible. For example, FtsZ in D.melanogaster Wolbachia and Brugia malayi Wolbachia are 92% identical,but FtsZ from Wolbachia, M. tuberculosis and E. coli share only 42-45%sequence identity.

The divergence of FtsZ sequences in different bacteria may allow forselection of inhibitors with substantially varied composition as well.It has been shown that M. tuberculosis FtsZ was unaffected byAlbendazole, while an Albendazole-like compound could significantlydisrupt FtsZ. Moreover, extensive variation on the benzimidazolestructure is evident when comparing FtsZ-disrupting compounds picked upby non-biased high-throughput screening. Even a benzthiazole related tothe hits NSC96932 and NSC339601 from our screen has been shown toexhibit FtsZ-disrupting activity. This openness of FtsZ to structurallydiverse permutations of benzimidazole creates the potential to designnarrow spectrum anti-FtsZ compounds for targeting Wolbachia and othertypes of bacteria.

Future structural characterization FtsZ molecules from Wolbachia andother bacterial species will aid substantially to design newnarrow-spectrum drugs. Modeling of a putative benzimidazole binding sitehas been done, based upon site-specific mutations in beta tubulin thatcontrol benzimidazole susceptibility. Oddly, these residues arepredicted to be buried within the center of the beta-tubulin structure.Kinetic studies have definitively shown that benzimidazoles bind betatubulin and disrupt microtubule stability, however. One explanation toreconcile these findings is that an inter-domain movement withinbeta-tubulin exposes these key residues to enable benzimidazole binding.This binding site could be amenable to benzimidazole variants rangingwidely in size, as even Albendazole sulfoxide, a relatively smallbenzimidazole, remains partly exposed to solvent when wedged into thepredicted binding pocket of beta tubulin. Thus, armed with detailedunderstanding of FtsZ structure, the side arms of new benzimidazolescould be designed to permit compound binding to FtsZ substrates ofspecific types of bacteria while excluding others.

The invention claimed is:
 1. A method for targeting Wolbachia bacteriain a subject, the method comprising administering to the subject aformulation comprising Albendazole sulfone.
 2. The method of claim 1wherein the formulation is administered to the subject orally.
 3. Themethod of claim 1 wherein the formulation is administered to the subjectintravenously, intramuscularly or subdermally.
 4. The method of claim 1wherein the formulation is a sustained release formulation.
 5. Themethod of claim 1 wherein the formulation further comprises one or morepharmaceutically acceptable excipients, carriers, penetration enhancers,stabilizers or buffers.
 6. The method of claim 1 further comprisingadministering to the subject a Doxycycline compound.
 7. The method ofclaim 1, wherein the formulation is a controlled release formulation. 8.The method of claim 1, wherein the formulation disrupts Wolbachia FtsZin a disease model comprising B. malayi.
 9. The method of claim 1,wherein the subject is co-infected with Loa Loa.
 10. The method of claim1, wherein the administration kills the Wolbachia bacteria in thesubject.